diff --git a/board/czechlight/clearfog/mk-rauc-bundle.sh b/board/czechlight/clearfog/mk-rauc-bundle.sh
new file mode 100755
index 0000000..8d82432
--- /dev/null
+++ b/board/czechlight/clearfog/mk-rauc-bundle.sh
@@ -0,0 +1,24 @@
+#!/bin/sh
+
+RAUC_BUILD_DIR=${BUILD_DIR}/rauc-work-tmp
+RAUC_IMAGE=${BINARIES_DIR}/update.raucb
+ROOTFS_NAME=rootfs.tar.xz
+
+rm -rf ${RAUC_BUILD_DIR}
+mkdir ${RAUC_BUILD_DIR}
+rm -f ${RAUC_IMAGE}
+
+ln ${BINARIES_DIR}/${ROOTFS_NAME} ${RAUC_BUILD_DIR}/
+cat > ${RAUC_BUILD_DIR}/manifest.raucm << EOF
+[update]
+compatible=czechlight-clearfog
+version=dev
+
+[image.rootfs]
+filename=${ROOTFS_NAME}
+EOF
+
+rauc \
+  --cert ${BR2_EXTERNAL_CZECHLIGHT_PATH}/crypto/rauc-cert.pem \
+  --key ${BR2_EXTERNAL_CZECHLIGHT_PATH}/crypto/rauc-key.pem \
+  bundle ${RAUC_BUILD_DIR} ${RAUC_IMAGE}
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index 5fdfe43..54ac972 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -13,7 +13,7 @@
 # BR2_TARGET_GENERIC_REMOUNT_ROOTFS_RW is not set
 BR2_ROOTFS_OVERLAY="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/overlay/ $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/overlay/"
 BR2_ROOTFS_POST_BUILD_SCRIPT="$(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/mk-empty-cfg-fs.sh $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/common/install-rauc-cert.sh"
-BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh"
+BR2_ROOTFS_POST_IMAGE_SCRIPT="support/scripts/genimage.sh $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/mk-rauc-bundle.sh"
 BR2_ROOTFS_POST_SCRIPT_ARGS="-c $(BR2_EXTERNAL_CZECHLIGHT_PATH)/board/czechlight/clearfog/genimage.cfg"
 BR2_LINUX_KERNEL=y
 BR2_LINUX_KERNEL_CUSTOM_VERSION=y
@@ -38,7 +38,7 @@
 BR2_TARGET_ROOTFS_EXT2_4=y
 BR2_TARGET_ROOTFS_EXT2_SIZE="256M"
 BR2_TARGET_ROOTFS_EXT2_MKFS_OPTIONS="-O ^64bit -e panic"
-# BR2_TARGET_ROOTFS_TAR is not set
+BR2_TARGET_ROOTFS_TAR_XZ=y
 BR2_TARGET_UBOOT=y
 BR2_TARGET_UBOOT_BUILD_SYSTEM_KCONFIG=y
 BR2_TARGET_UBOOT_CUSTOM_VERSION=y